The present invention is related to aromatic amines and discoloration therein as well as the use of discoloration inhibitors in aromatic amines.
Aromatic amines which have been freshly distilled are "water white". By water white, I mean that aromatic amines are clear, without sediment or precipitant or bodies in suspension. I also mean that they are colorless.
I have found that aromatic amines such as alkylated anilines and alkylated aromatic diamines are subject to discoloration upon standing or exposure to air or oxygen. The normally water white substituted aromatic amines, upon standing, tend to turn to a straw or dust color and eventually will turn to a totally black color which is unsuitable for further processing of the alkylated aromatic amine. Typically, the substituted aromatic amines are used as intermediates in the preparation of polymers such as polyurethanes, insecticides, herbicides, and other products. Accordingly, there is a need to provide a method and composition for stabilizing the color of the alkylated aromatic amines.